This paper explores the directions for the application of unmanned aerial vehicles in the provision of security to vital elements of a country’s critical infrastructure. The analysis focuses on two paths of development: the first one refers to the transportation system, the latter is related to the gas supply network – the basic components of a country’s critical infrastructure. The first section of this paper will examine the current state of knowledge in the field, and is designed as a reference of terminology pertaining to unmanned aerial vehicles (definitions and classification). The section shall furthermore provide a basis for and a contribution to the developed conceptual-semantic framework for UAV research. The first direction of development is described in terms of the characteristics and assumptions of the system; this includes an overview of the specific requirements of the unmanned platform itself, as well as the elements of the system, such as a local monitoring centre and other components. Furthermore, this section provides the overview of the designated mobile application, whose development is expected to improve the efficiency of system operation, which is a conceptual novelty considering similar developments. The second direction concerns the development of an unmanned system of production, storage, and use of chemical and radioactive substances, including pipelines for hazardous substances. The programme that fits perfectly in the framework of the second considered branch of development is “Cricket” [Polish: “Świerszcz”] – a programme implemented in the periodic inspection of gas supply infrastructure. The description of the programme in question included specifying the technical and operational requirements for the fight devices as well as for the equipment.
The paper shows the results of the study into the effectiveness of structural laminate joining solutions by conducting comparative shear strength tests of adhesive and riveted joints of GFRP laminate components. In addition, the work shows selected surface roughness and texture parameters, a detailed analysis of failure forces measured in tensile test as well as analysis of failure modes of combined specimens. The theoretical and experimental sections of this paper describe the riveted and adhesive joints of the laminate substrates, and have led to several important conclusions in analysis of force and failure for two joint formations.
PL
Celem artykułu było przeprowadzenie analizy porównawczej wytrzymałości połączeń nitowanych i klejowych kompozytów polimerowych wzmocnionych włóknem ciągłym stosowanych w elementach konstrukcji lotniczych.
The aim of the paper is to validate the use of measurement methods in the study of GFRP joints. A number of tests were carried out by means of a tensile machine. The studies were concerned with rivet connection of composite materials. One performed two series of tests for two different forces and two fibre orientations. Using Finite Element Method (FEM) and Digital Image Correlation (DIC), strain maps in the test samples were defined. The results obtained with both methods were analysed and compared. The destructive force was analysed and, with the use of a strain gauge, the clamping force in a plane parallel to the annihilated sample was estimated. Destruction processes were evaluated and models of destruction were made for this type of materials taking into account their connections, such as riveting.
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W artykule dokonano analizy materiałów stosowanych we współczesnych konstrukcjach lotniczych, skupiając uwagę na strukturze płatowca samolotu. Przedstawiono wybrane problemy dotyczące projektowania i eksploatacji struktur lotniczych, z uwzględnieniem kompozytów oraz metali lekkich (aluminium, tytan i ich stopy). Omówiono problemy obróbki mechanicznej, takiej jak: szlifowanie, wykonywanie otworów itp. Przedstawiono problemy analizy metodą elementów skończonych (MES), na podstawie dwóch próbek wykonanych ze stopu aluminium oraz z włóknistego kompozytu szklanego. Zaprezentowano różnice w budowie oraz modelowaniu tych materiałów, wynikające z ich różnorakiej struktury (izotropia i anizotropia). Dokonano analizy mechaniki niszczenia metalu, porównując go z kompozytem. Przedstawiono tendencje oraz kierunki rozwoju lotniczych materiałów konstrukcyjnych z uwzględnieniem materiałów metalowo-kompozytowych. Przedmiotem niniejszego artykułu są współczesne materiały konstrukcyjne wykorzystywane w strukturach lotniczych. Celem publikacji jest porównanie współczesnych materiałów konstrukcyjnych (kompozytów oraz metali) oraz przedstawienie wybranych problemów w ich projektowaniu, konstruowaniu oraz eksploatacji. Tezy, uzasadnione wynikami analizy symulacji oraz badań, zostały przedstawione w treści i podsumowaniu artykułu.
EN
The article presents the analysis of materials used in modern air structures, with the focus on the structure of the aircrafts airframe. There were presented selected problems concerning the design and operation of aeronautical structures with composites and light metals (aluminum, titanium and their alloys). The article is focused on mechanical treatment, such as grinding, making holes and others. The paper describes the problems of analysis of Finite Element Method (FEM), on the basis of two samples made of aluminium alloy and fiberglass composite and the differences between the constructions of these materials and modeling of these material resulting from their different structure (isotropy and anisotropy). The article also includes an analysis of the mechanics of destruction of metal comparing it to composite material. There were presented the trends and the ways of developments of the structural material, including air materials metal-composite. The object of this article is to show modern construction materials used in aerospace structures. The purpose of the publication is to compare the modern construction materials (composites and metals) and to present selected problems in their design and operation of construction. The results of simulation analysis and researches were presented in the content and summary of the article.
The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test one type of glass fabric was used (Interglas 92140) from which two types of composite samples were prepared. In each sample the same type of fiber with the same fiber orientation – 3 layers - was used. The samples had dimensions of 100×100 mm and thickness of approximately 1 mm. The composite probes were located in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 15 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fibre orientations and the value of feed force, damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.
The main goal was to determine if transducers based on piezoelectric materials are suitable for strain calculations in thin GFRP specimens. Numerous experimental studies, both physical and numerical, performed by the authors, have shown that there is a huge influence of bonded piezoelectric transducer on the overall stiffness of the measured object. The paper presents tensile test performed on strength machine with Digital Image Correlation strain and deflection observations. Test were compared with FEM models for detailed investigation. The main conclusion is piezoelectric transducers has huge influence on local stiffness of measured object. That is critical especially when they are used as strain sensors, when presence of sensor is influencing to measured results.
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